Mr Idris said this season typically runs from October to May, with May being the peak month. Outbreaks typically occur during the dry season, when human exposure to rodents is highest.
The Director General of the Nigeria Centre for Disease Control and Prevention (NCDC), Jide Idris, has attributed the seasonal surge in Lassa fever cases--caused by contact with food contaminated by rat faeces --to the effects of climate change.
He said this on Monday during a press briefing at the NCDC headquarters in Abuja.
According to the DG, climate and environmental factors are responsible for the seasonal transmission of Lassa fever in the country.
This season typically runs from October to May, with May being the peak season. Outbreaks typically occur during the dry season, when human exposure to rodents is highest.
When climate change disrupts the rain pattern, leading to longer dry seasons, it lengthens the high transmission period. This increases rodent activity in homes and increases the chances of human exposure.
According to the DG, the influence of these factors on rodent-induced illness must be studied to combat any other potential outbreak actively.
He said: "Lassa fever is becoming something you see as seasonal because of climate change. It affects the transmission rate, especially in agrarian communities.
"We are in season for increasing transmission, and we are starting to get concerned about what we see now. But these are things, however, that are constantly watched."
Mr Idris said the agency has begun collaborating with other relevant government agencies to identify multiple ways to control the spread.
According to him, the agency's goal is to prevent the recurrence of another outbreak.
"So we will continue to see more cases. There's no doubt about that. We can't stop it. But the other is that when we see these cases or when they are reported to us, they are immediately treated; they are looked after so that the victims will not die," he noted.
Lassa fever impact
Mr Idris stated that, unlike other endemic diseases in the country, persons infected with the disease are at a high risk of death as case fatality for the disease is high.
He pointed out that Lassa fever, caused by the Lassa virus, affects the body by targeting multiple systems, leading to mild to severe symptoms.
In mild cases, infected persons will likely experience mild fever, fatigue, nausea, sore throat, and weakness.
However, for severe cases, the DG said Lassa fever damages the kidney, causing blood loss and causing the patients to require dialysis.
"This is part of the issues we are working to solve," he said.
"Earlier in the year, we purchased some dialysis machines and distributed them to some facilities across the country.
"But again, not all doctors can use dialysis machines. They are only manned by nephrologists. So those hospitals where they have nephrologists are recommended for patients with severe cases of Lassa fever," he added.
He also noted that an Emergency Operations Center (EOC) has been activated to ensure effective disease control.
This means a coordinated response system is being implemented to manage and contain an outbreak effectively.
Control measures
The DG has also heightened surveillance and distributed critical medical supplies, infection prevention and control (IPC) materials, and diagnostic tools in preparation for an outbreak season.
He stated that the agency's risk assessment showed a high-risk level for the next outbreak season, with states with high burdens at a higher risk.
Mr Idris said this assessment result is concerning as the government is working to prevent an outbreak with more suspected dandy confirmed cases.
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He indicated that Nigeria recorded a higher number of cases in 2024 than it did in 2023.
Nigeria recorded 9,492 suspected cases, 1,154 confirmed cases, and 190 deaths in 2024.
Six states--Ondo, Edo, Bauchi, Taraba, Benue, and Ebonyi--account for 89 per cent of the confirmed cases.
However, Mr Jide noted an alarming increase in Lassa fever cases and deaths in the last four weeks.
He also said the case fatality rate has consistently remained high, over 13 per cent.
"We have noted a rise in the number of suspected cases compared to a similar timeline in 2023. This, however, could be attributed to the increased and enhanced surveillance.
"Most cases continue to emerge from endemic areas, like Bauchi, Ondo, Edo, Taraba Ebonyi, and Enugu, underscoring the need for targeted interventions in these states," he noted.
